Towards a facile synthesis of triarylethanones:: palladium-catalyzed arylation of ketone enolates under homogeneous and heterogeneous conditions

The palladium-catalyzed regioselective alpha-monoarylation of deoxybenzoins and alpha,alpha-diarylation of acetophenones provides general, efficient access to 1,2,2-triarylethanones. After a comprehensive search for suitable experimental conditions to optimize such transformations, both reactions are alternatively conducted by means of either commercially available polymer-anchored catalysts or a very simple homogeneous catalytic system, thus avoiding the use of complex ligands. In addition, the synthesis of deoxybenzoins employing polymer-supported fibrous palladium catalysts is reported for the first time, and the excellent catalyst recycling properties suggest applicability to industrial purposes. (C) 2004 Elsevier Ltd. All rights reserved.